package com.mzy.datepackage.M2021.Dec.seven;

/**
 * @author Ives
 * * @date 2021/12/7
 */
public class Demo {
  public static void main(String[] args) {
    String s ="aa";
    String concat = s.concat(";");
    StringBuffer serviceNumber = new StringBuffer();
    int i = serviceNumber.indexOf(concat);
    System.out.println(i);
    System.out.println(concat);
    System.out.println(serviceNumber.append("xxx")); // StringBuffer追加
  }
}
